class Dog:
    def print_self(self):
        print("大家好，我是xxxxx")

class Xiaotq(Dog):
    def print_self(self):
        print("hello ,everybody，我是xxx")


#多态
def print_content(temp):
    temp.print_self()

d = Dog()
print_content(d)

x = Xiaotq()
print_content(x)

